In vitro and in vivo techniques will be used to study the effects of ethanol (ETOH) on the hypothalamo-hypophysial-luteinizing hormone (LH) axis. The in vitro studies will be used to determine the effects of ETOH alone or in combination with either dopamine (DA), norepinephrine (NE) or prostaglandin E2 (PGE2) on the release of radioimmunoassayable luteinizing hormone-releasing hormone (LHRH) from isolated male rat median eminences (ME). For the in vivo studies, radioimmunoassay (RIA) and immunocytochemical (ICC) techniques will be used to determine the effects of ETOH administration of LHRH concentration of the hypothalamus and ME of normal, ovariectomized and pregnant rats. These correlative techniques will also be used to ascertain any effects that prenatal ETOH exposure may have on LHRH production and/or secretion patterns in fetal and early postnatal animals. Light and electron microscopic ICC techniques for LHRH will be used to visualize any changes which might occur in discrete regions of the hypothalamus and ME that may be affected by ETOH, whereas RIA will determine any quantitative changes in hypothalamic LHRH content. Also, RIA for LH will be used to evaluate any changes which might occur in the blood. In addition, electron microscopic ICC will be used to determine any subcellular changes in LHRH perikarya. This combined qualitative and quantitative approach will allow us to evaluate any endocrine changes due to ETOH, as well as add to our overall understanding of the hypothalamo-hypophysial control system as it relates to neuroendocrinology and reproduction.